Commit b463a3c3 authored Mar 17, 2024 by Linus Torvalds

Merge tag 'perf-urgent-2024-03-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 perf event fixes from Ingo Molnar:

 - Work around AMD erratum to filter out bogus LBR stack entries

 - Fix incorrect PMU reset that can result in warnings (or worse)
   during suspend/hibernation

* tag 'perf-urgent-2024-03-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/core: Avoid register reset when CPU is dead
  perf/x86/amd/lbr: Discard erroneous branch entries

parents 032e22fe ad8c9128

arch/x86/events/amd/core.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -604,7 +604,6 @@ static void amd_pmu_cpu_dead(int cpu)

		kfree(cpuhw->lbr_sel);
		cpuhw->lbr_sel = NULL;
		amd_pmu_cpu_reset(cpu);

		if (!x86_pmu.amd_nb_constraints)
		return;

arch/x86/events/amd/lbr.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -173,9 +173,11 @@ void amd_pmu_lbr_read(void)

		/*
		* Check if a branch has been logged; if valid = 0, spec = 0
		* then no branch was recorded
		* then no branch was recorded; if reserved = 1 then an
		* erroneous branch was recorded (see Erratum 1452)
		*/
		if (!entry.to.split.valid && !entry.to.split.spec)
		if ((!entry.to.split.valid && !entry.to.split.spec) \|\|
		entry.to.split.reserved)
		continue;

		perf_clear_branch_entry_bitfields(br + out);